The invention relates to substituted 4-benzylaminoquinolines and their hetero analogs, and to pharmaceutically acceptable salts and physiologically functional derivatives thereof.
The formation of gallstones is, in addition to a number of factors, essentially determined by the composition of bile, in particular by the concentration and the ratio of cholesterol, phospholipids and bile salts. A precondition for the formation of cholesterol gallstones is the presence of cholesterol-supersaturated bile (Carey, M. C. and Small, D. M.; xe2x80x9cThe physical chemistry of cholesterol solubility in bile. Relationship to gallstone formation and dissolution in man,xe2x80x9d J. Clin. Invest. 61:998-1026 (1978)).
A great therapeutic demand exists for both the medical dissolution of gallstones and for the prevention of gallstones forming as an alternative to surgical removal of gallstones.
The invention provides compounds which are able to prevent the formation of gallstones by preventing the supersaturation of bile with cholesterol, or by delaying the formation of cholesterol crystals from supersaturated bile.
The invention comprises compounds of formula I: 
wherein:
G is 
K is xe2x80x94OR(7), xe2x80x94NR(7)R(8), xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94CO2H, xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94SO3H, xe2x80x94NHxe2x80x94CH2xe2x80x94CO2H, xe2x80x94N(CH3)CH2CO2H, xe2x80x94HNxe2x80x94CHR(9)CO2H, or xe2x80x94Ocat, where cat is a cation such as, for example, an alkali metal or alkaline earth metal ion or a quaternary ammonium ion;
R(7), R(8) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
R(9) is (C1-C4)-alkyl, benzyl, xe2x80x94CH2xe2x80x94OH, H3CSCH2CH2xe2x80x94, HO2CCH2xe2x80x94, or HO2CCH2CH2xe2x80x94;
R(1) to R(6) are independently of one another selected from hydrogen, xe2x80x94OR(10), xe2x80x94SR(10), xe2x80x94NR(10)R(13), xe2x80x94OCOR(10), xe2x80x94SCOR(10), xe2x80x94NHCOR(10), xe2x80x94OPO(OR(10))2, xe2x80x94OSO2OR(10), xe2x80x94R(10), and one or more pairs of R(1) and R(2), R(3) and R(4), R(5) and R(6), wherein these pairs optionally form a carbonyl group, wherein only one of the radicals R(1) to R(6) is a bond to L;
R(10), R(13) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
L is (C1-C15)-alkyl, wherein one or more CH2 units is optionally replaced by xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94NR(11)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94SO2xe2x80x94, or xe2x80x94Sxe2x80x94;
R(11) is hydrogen, (C1-C8)-alkyl, R(12)xe2x80x94COxe2x80x94, phenyl, or benzyl;
xe2x80x83R(12) is hydrogen, (C1-C8)-alkyl, phenyl, or benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
P is 
xe2x80x83wherein: 
R(16) to R(24) are independently of one another selected from hydrogen, F, Cl, Br, I, (C1-C4)-alkyl, CN, NO2, NR(25)R(26), OR(25), OCOR(25), COR(25), COOR(25), CONR(25)R(26), SO2R(25), SO2OR(25), and SO2NR(25)R(26), wherein an alkyl radical is optionally substituted one or more times by fluorine, and wherein only one of the radicals R(16) to R(24) is a bond to L; and
R(25), R(26) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an alkyl radical is optionally substituted one or more times by fluorine;
or any pharmaceutically acceptable salts or physiologically functional derivatives thereof.
In another embodiment, the compounds of formula I have one or more radical(s) with the following meaning(s):
G is 
K is OR(7), xe2x80x94NR(7)R(8), xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94CO2H, xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94SO3H, xe2x80x94NHxe2x80x94CH2xe2x80x94CO2H, xe2x80x94N(CH3)CH2CO2H, xe2x80x94HNxe2x80x94CHR(9)CO2H, or xe2x80x94Ocat, where cat is a cation such as, for example, an alkali metal or alkaline earth metal ion or a quaternary ammonium ion;
R(7), R(8) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
R(9) is (C1-C4)-alkyl, benzyl, xe2x80x94CH2xe2x80x94OH, H3CSCH2CH2xe2x80x94, HO2CCH2xe2x80x94, or HO2CCH2CH2xe2x80x94;
R(1), R(3), R(5) are independently of one another selected from hydrogen, xe2x80x94OR(10), NR(10)R(13), xe2x80x94OCOR(10), and xe2x80x94NHCOR(10);
R(10), R(13) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
L is (C1-C8)-alkyl, wherein one or more CH2 units is optionally replaced by xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94NR(11)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94, or xe2x80x94SO2xe2x80x94;
R(11) is hydrogen, (C1-C4)-alkyl, R(12)xe2x80x94COxe2x80x94, phenyl, or benzyl;
R(12) is hydrogen, (C1-C4)-alkyl, phenyl, or benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
P is 
R(16) to R(24) are independently of one another selected from hydrogen, F, Cl, Br, (C1-C4)-alkyl, NR(25)R(26), OR(25), OCOR(25), COR(25), COOR(25), and CONR(25)R(26), wherein an alkyl radical is optionally substituted one or more times by fluorine, and wherein only one of the radicals R(16) to R(24) is a bond to L; and
R(25), R(26) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an alkyl radical is optionally substituted one or more times by fluorine;
or any pharmaceutically acceptable salts or physiologically functional derivatives thereof.
Compounds of formula I are found in yet another embodiment in which one or more radical(s) has or have the following meaning(s):
G is 
K is xe2x80x94OR(7), xe2x80x94NR(7)R(8), xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94CO2H, xe2x80x94HNxe2x80x94CH2xe2x80x94CH2xe2x80x94SO3H, xe2x80x94NHxe2x80x94CH2xe2x80x94CO2H, xe2x80x94N(CH3)CH2CO2H, or xe2x80x94Ocat, where cat is a cation such as, for example, an alkali metal or alkaline earth metal ion or a quaternary ammonium ion;
R(7), R(8) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
R(1) is hydrogen, or xe2x80x94OH;
L is (C1-C5)-alkyl, wherein one or more CH2 units is optionally replaced by xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94NR(11)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94, or xe2x80x94SO2xe2x80x94;
R(11) is hydrogen, (C1-C4)-alkyl, R(12)xe2x80x94COxe2x80x94, phenyl, or benzyl;
R(12) is hydrogen, (C1-C4)-alkyl, phenyl, or benzyl, wherein an aromatic group is optionally substituted from 1 to 3 times by radicals independently of one another selected from F, Cl, CF3, methyl, and methoxy;
P is 
R(16) to R(24) are independently of one another selected from hydrogen, F, Cl, (C1-C4)-alkyl, NR(25)R(26), OR(25), OCOR(25), COR(25), COOR(25), and CONR(25)R(26), wherein an alkyl radical is optionally substituted one or more times by fluorine, and wherein only one of the radicals R(16) to R(24) is a bond to L; and
R(25), R(26) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an alkyl radical is optionally substituted one or more times by fluorine;
or any pharmaceutically accept able salt thereof.
Of further interest are compounds of formula I in which one or more radicals have the following meaning(s):
G is 
R(1) is hydrogen or xe2x80x94OH; p2 L is (C1-C5)-alkyl, wherein one or more CH2 units is optionally replaced by xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94NR(11)xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94, or xe2x80x94SO2xe2x80x94;
P is 
xe2x80x83wherein:
R(16) to R(24) are independently of one another selected from hydrogen, F, Cl, (C1-C4)-alkyl, NR(25)R(26), OR(25), OCOR(25), COR(25), COOR(25), and CONR(25)R(26), wherein an alkyl radical is optionally substituted one or more times by fluorine, and wherein only one of the radicals R(16) to R(24) is a bond to L; and
R(25), R(26) are independently of one another selected from hydrogen, (C1-C4)-alkyl, phenyl, and benzyl, wherein an alkyl radical is optionally substituted one or more times by fluorine;
or any pharmaceutically acceptable salt thereof.
If the compounds of formula I contain one or more centers of asymmetry, these may have either the S or the R configuration. The compounds may be in the form of optical isomers, diastereomers, racemates or mixtures thereof.
The expression xe2x80x9cwherein an alkyl radical is optionally substituted one or more times by fluorinexe2x80x9d also includes perfluorinated alkyl radicals. Alkyl radicals may be either straight-chain or branched.
Pharmaceutically acceptable salts, by reason of their greater solubility in water compared with the initial or basic compounds, are particularly suitable for medical applications. These salts must have a pharmaceutically acceptable anion or cation. Suitable pharmaceutically acceptable acid addition salts of the novel compounds are salts of inorganic acids such as hydrochloric, hydrobromic, phosphoric, metaphosphoric, nitric, sulfamic, and sulfuric acid, and organic acids such as acetic, benzenesulfonic, benzoic, citric, ethanesulfonic, fumaric, gluconic, glycolic, isethionic, lactic, lactobionic, maleic, malic, methanesulfonic, succinic, p-toluenesulfonic, tartaric, and trifluoroacetic acid. It is preferred to use the chloride salt for medical purposes. Suitable pharmaceutically acceptable basic salts are ammonium salts, alkali metal salts (such as sodium and potassium salts) and alkaline earth metal salts (such as magnesium and calcium salts).
Salts with a pharmaceutically unacceptable anion likewise belong within the framework of the invention as useful intermediates for the preparation or purification of pharmaceutically acceptable salts and/or for use in nontherapeutic, for example in vitro, applications.
The term xe2x80x9cphysiologically functional derivativexe2x80x9d used herein designates any physiologically tolerated derivative of a compound of formula I, for example an ester, which is able on administration to a mammal such as, for example, a human to form (directly or indirectly) a compound of formula I or an active metabolite thereof.
The physiologically functional derivatives include prodrugs of the instant inventive compounds. Such prodrugs can be metabolized in vivo to one of the instant inventive compounds. These prodrugs may or may not themselves have activity.
The compounds of the invention may also exist in various polymorphous forms, for example as amorphous and crystalline polymorphous forms. All polymorphous forms of the compounds of the invention form part of the invention and are a further aspect of the invention.
All references to xe2x80x9ccompound(s) of formula Ixe2x80x9d hereinafter refer to compound(s) of formula I as described above, and their salts, solvates and physiologically functional derivatives as described herein.
The amount of a compound of formula I necessary to achieve the desired biological effect depends on a number of factors, such as the specific compound chosen, the intended use, the mode of administration, and the clinical condition of the patient.
The daily dose is generally in the range from 0.1 mg to 100 mg (typically from 0.1 mg to 50 mg) per day and per kilogram body weight, for example from 0.1 to 10 mg/kg/day. Tablets or capsules may contain dosages, for example, from 0.01 to 100 mg, typically from 0.02 to 50 mg. In the case of pharmaceutically acceptable salts, the aforementioned weight data relate to the weight of the salt of the compound of formula I.
For prophylaxis or therapy of the above mentioned conditions, compounds of formula I can be used directly as the compound itself, but are preferably used in the form of a pharmaceutical composition with a compatible carrier. The carrier must, of course, be compatible in the sense that it is compatible with the other ingredients of the composition and is not harmful to the patient""s health. The carrier may be a solid or a liquid or both and is preferably formulated with the compound as single dose, for example as a tablet which may contain from 0.05% to 95% by weight of the active ingredient.
Further pharmaceutically active substances may likewise be present, including further compounds of formula I. The pharmaceutical compositions of the instant invention can be produced by one of the known pharmaceutical methods which consist essentially of mixing the ingredients with pharmacologically acceptable carriers and/or excipients.
Pharmaceutical compositions of the invention are those suitable for oral and peroral (for example sublingual) administration although the most suitable mode of administration depends in each individual case on the nature and severity of the condition to be treated and on the nature of the particular compound of formula I used. The invention also embraces coated formulations and coated slow-release formulations. Formulations resistant to acid and gastric fluid are preferred. Suitable coatings resistant to gastric fluid comprise cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropylmethylcellulose phthalate, and anionic polymers of methacrylic acid methyl methacrylate.
Suitable pharmaceutical compounds for oral administration may be in the form of separate units such as capsules, cachets, pastilles, or tablets, each of which contains a defined amount of a compound of formula I; as powders or granules; as solution or suspension in an aqueous or nonaqueous liquid; or as an oil-in-water or water-in-oil emulsion. These compositions can, as already mentioned, be prepared by any suitable pharmaceutical method which includes a step in which the active ingredient and the carrier (which may consist of one or more additional ingredients) are brought into contact. In general, the compositions are produced by uniform and homogeneous mixing of the active ingredient with a liquid and/or finely dispersed solid carrier, after which the product is shaped if necessary. Thus, for example, a tablet can be produced by compressing or shaping a powder or granules of the compound, where appropriate with one or more additional ingredients. Compressed tablets can be produced by tableting the compound in free-flowing form, such as, for example, a powder or granules, and where appropriate, mixed with a binder, lubricant, inert diluent and/or one (or more) surface-active/dispersing agents in a suitable machine. Shaped tablets can be produced by shaping, in a suitable machine, the compound which is in powder form and has been moistened with an inert liquid diluent.
Pharmaceutical compositions suitable for peroral (sublingual) administration comprise suckable tablets which contain a compound of formula I with a flavoring, normally sucrose, and gum arabic or tragacanth, and pastilles which comprise the compound in an inert base such as gelatin and glycerol or sucrose and gum arabic.
The invention further relates to two processes for preparing the compounds of formula I.
Process A) This entails a compound of formula IIId, where X is halogen, such as Br or I, being reacted with a compound of formula IId in a Pd(0)-catalyzed coupling reaction. The HX liberated thereby is trapped by an auxiliary base (such as triethylamine or pyridine). 
R1, R3, R4, R5, K and P are defined as above. The ethynyl-bile acid derivatives of formula lid are prepared from suitable bile acid ketones. For this purpose, lithium acetylide is added onto keto-bile acids analogously to known processes (U.S. Pat. No. 5,641,767).
Process B) Carboxylic acids of formula IIIe (Rxe2x95x90OH) are reacted with compounds of formula IIe in a known manner in the presence of suitable coupling reagents such as, for example, TOTU (Chemiker Zeitung, 98:817(1974)), DCC/HOBt (J. Am. Chem. Soc., 77:1067 (1955)), or CMC/HOBt (J. Org. Chem., 21:439 (1956)), (see abbreviations below) forming an amide linkage. Carboxamides of formula IVe may also be formed by reacting activated carboxylic acid derivatives IIIe with compounds of formula IIe in the presence of an auxiliary base (for example, triethylamine or pyridine) in a manner known to the skilled worker. Exemplary activated carboxylic acid derivatives of formula lie are the corresponding chlorides (Rxe2x95x90Cl), imidazolides (R=1-imidazolyl; Angew. Chem. Int. Ed. Engl., 1:351 (1962)), or the mixed anhydrides with Clxe2x80x94COOEt or tosyl chloride. 
R1, R3, R4, R5, K and P are defined as above. The 3-ethanolamine-bile acid building blocks of formula IIe are prepared by known processes (Tetrahedron Lett., 34:817 (1993)).
Compounds of formula I and their pharmaceutically acceptable salts and physiologically functional derivatives have a beneficial effect on the composition of bile and prevent the formation of gallstones by preventing supersaturation of the bile with cholesterol, or by delaying the formation of cholesterol crystals from supersaturated bile. Compounds of the present invention can be employed alone or in combination with lipid-lowering active ingredients (see Rote Liste, chapter 58). The inventive compounds are particularly suitable for the prophylaxis and for the treatment of gallstones.
Compounds of formula I enter the hepatobiliary system and therefore act in these tissues. Thus, the absorption of water from the gall bladder is inhibited through inhibition of the apical NHE antiport of subtype 3 of the gall bladder epithelium, which results in a diluted bile.
Biological testing of the novel compounds was accomplished by measuring inhibition of the sodium/proton exchanger subtype 3.
The remaining activity of the human NHE-3 protein (expressed in the LAP1 cell line) was determined by measuring the recovery in the intracellular pH (pHi) after an acidification, which starts when the NHE is capable of functioning, even under bicarbonate-free conditions. For this purpose, the pHi was determined using the pH-sensitive fluorescent dye BCECF (Calbiochem, the precursor BCECF-AM is employed). The cells were initially loaded with BCECF. The BCECF fluorescence was determined in a xe2x80x9cratio fluorescence spectrometerxe2x80x9d (Photon Technology International, South Brunswick, N.J., USA) with excitation wavelengths of 505 and 440 nm and an emission wavelength of 535 nm, and was converted into the pHi using calibration plots. The cells were incubated in NH4Cl buffer (pH 7.4) (NH4Cl buffer: 115 mM NaCl, 20 mM NH4Cl, 5 mM KCl, 1 mM CaCl2, 1 mM MgSO4, 20 mM HEPES, 5 mM glucose, 1 mg/ml BSA; a pH of 7.4 is adjusted with 1 M NaOH) even during the BCECF loading. The intracellular acidification was induced by addition of 975 xcexcl of an NH4Cl-free buffer (see below) to 25 xcexcl aliquots of the cells incubated in NH4Cl buffer. The subsequent rate of pH recovery was recorded for 3 minutes. To calculate the inhibitory power of the substances tested, the cells were initially investigated in buffers in which complete or absolutely no pH recovery took place. For complete pH recovery (100%), the cells were incubated in Na+-containing buffer (133.8 mM NaCl, 4.7 mM KCl, 1.25 mM CaCl2, 1.25 mM MgCl2, 0.97 mM Na2HPO4, 0.23 mM NaH2PO4, 5 mM HEPES, 5 mM glucose, a pH of 7.0 was adjusted with 1 M NaOH). To determine the 0% value, the cells were incubated in an Na+-free buffer (133.8 mM choline chloride, 4.7 mM KCl, 1.25 mM CaCl2, 1.25 mM MgCl2, 0.97 mM K2HPO4, 0.23 mM KH2PO4, 5 mM HEPES, 5 mM glucose, a pH of 7.0 was adjusted with 1 M NaOH). Test solutions of the substances of interest were made up in the Na+-containing buffer. Recovery of the intracellular pH at the tested concentration of a substance was expressed as a percentage of the maximum recovery.
Results:
Example 1: remaining activity of hNHE3 at 30 xcexcM=26%
Example 2: remaining activity of hNHE3 at 30 xcexcM=33%
Example 3: remaining activity of hNHE3 at 30 xcexcM=22%
Example 6: remaining activity of hNHE3 at 30 xcexcM=39%
Example 11: remaining activity of hNHE3 at 30 xcexcM=61%
Example 13: remaining activity of hNHE3 at 30 xcexcM=40%
Example 14: remaining activity of hNHE3 at 30 xcexcM=52%
Example 15: remaining activity of hNHE3 at 30 xcexcM=65%
Example 16: remaining activity of hNHE3 at 30 xcexcM=27%
Example 17: remaining activity of hNHE3 at 30 xcexcM=36%
Example 18: remaining activity of hNHE3 at 30 xcexcM=36%
Example 20: remaining activity of hNHE3 at 30 xcexcM=56%
Example 23: remaining activity of hNHE3 at 30 xcexcM=16%
Example 24: remaining activity of hNHE3 at 30 xcexcM=29%
Example 25: remaining activity of hNHE3 at 30 xcexcM=18%
Example 26: remaining activity of hNHE3 at 30 xcexcM=52%
Example 27: remaining activity of hNHE3 at 30 xcexcM=54%
Example 28: remaining activity of hNHE3 at 30 xcexcM=69%
Example 29: remaining activity of hNHE3 at 30 xcexcM=61%
Example 30: remaining activity of hNHE3 at 30 xcexcM=48%
Example 31: remaining activity of hNHE3 at 30 xcexcM=69%
List of abbreviations: